With all due respect, I disagree.

From The American Psychological Association:

“The observed increase in average IQ scores of 3 points per decade has been reported by many as proof
that intelligence is not stable but is flexible with regards to environmental influences. However, none of the
authors in this extensive review of
the data, believes that intelligence is increasing at a rate greater than can be
attributed by eugenic means (breeding smarter people). Instead, they are looking at
the mechanisms of tests and how they are administered and interpreted in different time periods as people
become exposed to differing environments. That is, as the humans change their environment they change the
context in which their intelligence comes into play, and the testing methods must take this change into
account. Obviously they have not because the generational change in IQ results has increased,
without any evidence that today’s children are any smarter than their great-grand-parents. So it is back to
the drawing boards for the psychometricians who design the tests.
Neisser states that, “Whatever g may be, we at least know how to measure it. The accepted best measure,
which has played a central role in analyses of the worldwide rise in test scores, is the Raven Progressive
Matrices. This test, devised by Spearman’s student John C. Raven, was first published in 1938 and is now
available at several levels of difficulty. Arthur Jensen has said that Raven’s test ‘apparently
measures g and little else’ and that it ‘is probably the surest instrument we now possess for discovering
intellectually gifted children from disadvantaged backgrounds’. The Raven is of particular interest because it
shows such large IQ gains over time. In The Netherlands, for example, all male 18-year-olds take a version of
the Raven as part of a military induction requirement. The mean scores of those annual samples
rose steadily between 1952 and 1982, gaining the equivalent of 21 IQ points in only 30 years! This amounts to
a rate of no less than 7 points per decade — a figure confirmed by data from many other countries. What can
these increases mean?”
And later he states, “However, one may choose to interpret it, the fact that (unknown) environmental
factors are raising the mean IQ of Americans by 3 points per decade certainly shows that the environment
matters! The second proposition has quite a different status. Within a given population and a given range of
environments (e.g., those that are characteristic for White American males in 1998), genetic factors do make a
major contribution to individual differences. This has now been shown beyond a reasonable doubt
by the methods of behavior genetics, a discipline that is primarily concerned with variability. The
individuals in a given population differ on almost any measure one is likely to care about: their heights,
weights, Raven scores, IQ scores, or anything else. Every such measure has a distribution, often a bell-shaped
normal one. . . . Unfortunately, no one knows what it is about the environment that makes
this contribution to differences in IQ scores. Some obvious possibilities, such as the economic and
intellectual quality of children’s home situations, may be less important than was once believed. The
surprising fact is that when biologically unrelated children are raised in the same home (as in many cases of
adoption), the correlation between their IQ scores is unimpressive in childhood and near zero as they grow up!
This finding is important, but it is still negative: The aspects of the environment that do matter for the
development of intelligence have not yet been identified.”
Well, it doesn’t mean that people are getting any smarter but rather that the environment is impacting
how the results of IQ test scores are interpreted. That is, the expression of intelligence is not the same as
intelligence. If children today have a high level of exposure to visual-spatial stimulus such as computer
games, and IQ tests used 50 years ago used the same visual challenges to interpret intelligence, then the
tests may no longer be valid from one generation to the next for comparisons. Intelligence hasn’t changed, the
means to test intelligence has not kept up with human contextual flexibility to deal with a changing
environment.”
“Flynn states this fact succinctly, “Moreover, data whose quality cannot be challenged have posed the same
question. The Dutch military data, like those of Israel, Norway, and Belgium, are near exhaustive; but even
better, Vroon compared a sample of the total population of Dutch examinees with the scores of their own
fathers. There is simply no doubt that Dutch men in 1952 had a mean IQ of 79 when scored against 1982 norms.
Has the average person in The Netherlands ever been near mental retardation? Does it make sense to assume that
at one time almost 40% of Dutch men lacked the capacity to understand soccer, their most favored national
sport?”
Of course not, and that is why the Flynn effect is not taken seriously as an increase in real
intelligence, because we just do not see one generation as more intelligent than previous ones, on a myriad of
social indication scales. One would have to assume that the Greek philosophers were all mentally retarded, and
yet wrote with such elegance that we still read and try to interpret their works today. It is absurd. And not
one scholar in this book believes that real intelligence is changing but ever so slightly over time from
environmental effects.”

I have written extensively on this topic. Start at talk.origins: